Evolving agriculture and food system has entered into a consumer driven era with consumers demanding food safety, quality and convenience. Data collection can be helpful to analyze, design, develop, manage, control and characterize the biological and environmental processes in the agri-food industry. For example, sensors are used in the field for monitoring environmental parameters to help producers in conducting more efficient irrigation or pest control programs, on harvesting machinery for measuring yield per unit area, during storage for measurement of product temperature, for post-harvest grading and sorting of fruits and vegetables, and for online monitoring of process parameters during processing.
Sensors for the agri-food industry exhibit several differences compared to the traditional industrial sensors in terms of the measurement parameters as well as the environment. The users of agricultural sensors require inter-operable measurement framework and relative ease in the interpretation of sensor data. The agri-food processes are typically more variable due to biological nature (Neethirajan et al., 2009, Food and Bioprocess Technology 2(2): 115-121) thus sensors require the capability to handle this variability. Environment surrounding raw as well as processed agricultural materials is usually complex. Presence of multiple microorganisms and other biological agents further makes the sensing of parameters in agri-food industry very challenging.
Plant gas exchange, atmospheric gas monitoring, soil carbon dioxide (CO2) flux, biogas composition monitoring (Rego and Mendes, 2004, Sensors and Actuators B 103: 2-6; Reich, 1945, Food Industries 17(11):93-95) are areas in which monitoring CO2 can be used. Monitoring of CO2 with the help of sensors can be helpful in freeze damage detection in oranges (Tan et al., 2005, Post Harvest Biology and Technology 35: 177-182); in processing of alcohols and beverages (Marazuela et al., 1998, Applied Spectroscopy 51(10): 1257-1367), and in methanol and urea production.
Food packaging is often done under a modified atmosphere of nitrogen (N2), CO2, and oxygen (O2), specific to a product and with a purpose to prevent microbial spoilage. Carbon dioxide is widely used in modified-atmosphere packaging and a decrease in its concentration is a sign of leakage in a package. Freshness and safety of modified atmosphere food packages can be determined by detection of CO2 concentrations (Smolander et al., 1997, Trends in Food Science and Technology 8: 101-106; Jones, 1923, Canadian Chemistry and Metallurgy 7(7): 172-174). High CO2 levels can affect quality of French fries during processing and therefore, monitoring of CO2 levels can be used for controlling ventilation in potato storage facilities (Jayas et al., 2001, Canadian Biosystems Engineering 43(5): 5-12).